It is my understanding that genetics plays a significant role in sprint speed. Fortunately, I have always been a fast sprinter and enjoy sprinting over any kind of long distance running.

I presume that this genetic effect also applies to the other muscles of my body (I have a long throw, for example) so I was wondering how I could capitalise on this - are there any particular exercises that would make the most of my muscle composition? Or would any high intensity exercise be doing that?

I'm a little unclear on the specific genetic adaptation you refer to. Are you saying that you're just strong or naturally athletic, or that you're specifically a good sprinter, or that your muscles are naturally "fast", or something else?
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Dave LiepmannOct 10 '11 at 21:25

I think there is a profit opportunity for the fitness industry here: "Subscribe to a one-year premium gym membership and get a genetic muscle test for FREE! ". (The gym needs to cooperate with a molbio lab for this). "Develop a fitness plan optimized for your muscle type: Appointments with our personal trainers 30% OFF"
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knbJan 14 '12 at 11:54

Fast-twitch fibers allow one to generate a relatively high amount of
force in a short period. The take-off motion in a sprint and long jump
(when the foot is in contact with the ground for a millisecond) are
perfect examples of this.

as opposed to:

Slow-twitch fibers, on the other hand, come into play during the pure
endurance aspect of these events. Fatigue resistance, at the expense
of fast rate force production, is the hallmark of these fibers.

You had the right idea with high-intensity exercises, they develop the fast twitch fibers while low-intensity endurance exercises develop the slow twitch fibers.

Add one or two session of longer sprints to your weekly workout.
Going all-out for more than 50 meters is extremely tiring, so run
these sprints at around 85 percent effort for the best results.
Focus on quickness and fluidity of motion.

Make time for weight training. Research studies show a direct link
between maximum strength and overall speed, so using heavy weights
to make yourself stronger will beef up your fast twitch fibers.

Isometrics, as it pertains to muscle training, involves tensing
muscles against other muscles or against an immovable object while the
length of the muscle remains unchanged. For isometric training to be
effective, this muscular tension must be maintained over a certain
period of time.

Fast twitch fibers are used for explosive strength and maximum strength.

Olympic lifts make great use of fast twitch muscle fibers (explosive strength). Powerlifting does too, but not as much as Olympic lifting (maximum strength). Actually most sports benefit more from faster twitch fibers than slow twitch fibers. Basketball benefits a great deal from explosive strength.